Blackboard-eraser.



F. A. HOLBROOK. BLAGKBOARD ERASBR.

APPLoATIoN FILED JUNE 2, 1913.

Patented Apr. 21, 1914.

MIL' M6 COLUMBIA PLANOGRAPH CD.. WASHINGTON. D. c.

UNITED STATES PATENT OFFICE.

FREDERICK A. I-IOLBROOK, OF CHICAGO, ILLINOIS, ASSIGNOB. T'O CAXTON SCHOOL SUPPLY COMPANY, OF CHICAGO, ILLINOIS, A. CORPORATION 0F ILLINOIS.

BLACKBOARD-ERASER.

Loa-reas.

i Specification of Letters Patent.

Patented Apr. 21, 1914.

To all whom it may concern:

Be it known that I, FREDERICK A. I-IoL- nnoox, a citizen of the United States, and a resident of Chicago, in the countyV of Cook and State of Illinois, have invented certain new and useful Improvements in Blackboard-Erasers; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the letters ot reference marked thereon, which form a part of this specification.

This invention relates to blackboard erasers, and more particularly to that class or type of such devices in which the body or rubbing portion of the eraser comprises a series or plurality of strips ot erasing material, such as felt or the like, arranged side by side and secured with their inner or rear edges against the inner tace of the back or handle of the eraser. l

An eraser embodying my invention comprises means for binding or holding the several strips of erasing material forming the body or rubbing portion of the eraser together in a compact or comparatively solid or rigid mass and prevents said strips from spreading apart except at their outer or rubbing edges, so that the entrance of chalk dust and its retention between the strips, in any considerable quantities, will be prevented, thereby making the eraser more sanitary, while, at the same time, the inner edges of said several strips will not be liable to become loosened or detached from the back in the use of the eraser.

rlhe invention consists in the matters here- 'matter described and more particularly pointed out in the appended claims.

In the accompanying drawings illustrating my invention: Figure 1 is a perspective view of an eraser embodying my invention; Fig. 2 is a sectional view taken on line Q-Q of Fig. 3; Fig. 3 is a sectional view taken on line 33 of Fig. 2.

rIhe eraser shown in the accompanying drawings, and embodying my invention,

comprises a rigid back or handle A and a.

series or plurality of strips of erasing matef rial B, B, such as felt or the like, arranged side by side with their inner edges extending lengthwise of the back A and secured to the inner face of said back in any suitable manner, but preferably by glue. The outer longitudinal margins of said strips B, B are the rubbing edges thereof and form the rubbing surface of the eraser. As shown in the drawings, the strips B, B are slightly shorter thanthe length of said back or handle A and are of such thickness that when arranged side by side, the aggregate thickness of said strips B, B will be somewhat less than the width of the back or handle.

In order to bind or hold the several strips B, B together in a compact form, or comparatively solid or rigid mass, and to prevent said strips 'from spreading apart except at their outer or rubbing edges, so that the inner edges of the several strips will not be loosened from the back or handle A of the eraser in the use of the same, said several strips B, B are tightly bound together by mea-ns of a iiexible binding member C. Said binding member C is inserted through the several strips B, B at a plurality of points intermediate the back or handle A and the outer or rubbing edges of said strips and has looped portions thereof engaging the strips at each side of the eraser; said looped portions extend longitudinally of the strips that .they engage and are held in engagement with such strips by the portions that are inserted through the several strips, and serve to hold the side strips tightly against the several intermediate strips. The ends of the binding member C are united or tied together in a knot D intermediate the strips at the sides of the eraser.

In the construction shown in the drawings, the binding memberC is in the form of a tape and is applied in the following manner: Said tape C is inserted or threaded transversely through theseveral strips B, B

adjacent to one end of the eraser and. at a point preferably about midway between the back or handle A and the outer or rubbing edges of the strips B, B; the portion of the tape extending through said strips at this point being indicated by c. The tape is then looped at each side of the eraser and is inserted or threaded transversely through said several strips B, B at a point intermediate 4the portion c and the opposite end oi the eraser and about midway between the back or handle A and the outer or rubbing edges Vof said strips; the portions of the tape extending through the strips at this intermediate point cross each other, as shown in Fig. 8, and are indicated by c', c2, respectively. Said tape C is drawntaut and the looped l the crossed portions 0,

portions c3, c3 thereof at each side of the eraser and connecting the end portion c with the cross portions c, c2, are brought tightly against the strips at the side of the eraser. Said portions c3, c3 extend longitudinally of the strips which they engage and are located about midway between the back -A and the rubbingl or outer edges` of said strips. The remaining or free portions ot the tape are again looped and end portions 04, c5 thereoi2 are inserted or threaded from opposite sides of the eraser transversely through several of the strips B, B adjacent to the end ot the eraser opposite the portion c until the free ends of the tape meet and at which point said free ends are tied in a knot As shown in the drawings, the end portions c4, c5 each extend through an equal number of strips B, B, and the knot D is between the innermost or central of said lstrips B, B. The tape C is of course drawn taut before its ends are tied together, and the looped portions c6, c thereof, connecting c2 with the end portions ct, c5, are drawn or brought tightly against and extend longitudinally of the strips at each side of the eraser, as in the case of the portions c3, o3 of said tape, mentioned above (see Fig. 3). Said looped portions c3, 0G on one side of the eraser, and c3, 0G on the opposite side of the eraser, constitute in effect one portion for each side of the eraser and extend substantially the full length of the strips and are located midway between the back or handle A and the outer or rubbing edges of the strips.

The binding member or tape C, inserted through theseveral strips B, B in the manner as described and shown in the drawings, binds or holds the several. strips B, B together throughout their length in a comparatively compact form. Said tape or binding member C, being located in the position shown, namely, preferably about midway between the back or handle A and the outer or rubbing edges of the several strips Bpermits the flexing or spreading apart of the portions of the strips between the tape and the outer or rubbing edges of said strips, when the eraser is in use, so as to give the desired yielding quality to the rubbing surface of the eraser. Said tape or binding` member C, however, holds the portions ot the. several strips between the tape and the handle or vback A firmly together and in contact with each other, and prevents the flexing or spreading apart of such portions of said strips, at all times when the eraser is in use, and consequently the inner ends oi the strips do not become loosened from the back or handle A. In other words, the binding member C prevents the weakening of the connection between the inner ends of the strips and the back or handle ,A in the use of the eraser. The portions of the several strips between the binding member or tape C and the back or handle A being bound together in a comparatively compact form gives a certain amount of rigidity to the body or rubbing portion of the eraser. The eraser may be forced or pressed against a blackboard or other surface without breaking down the strips or spreading apart the strips except aft their outer ends.

A further advantage of the construction illustrated is that the strips, beingheld in compact form as stated, will not spread apart in use in a. manner to permit the chalk dust entering between the strips, so that substantially all of the chalk removed .from a blackboard by the use of the eraser will fall into the trough provided therefor. Prior forms of erasers in which the felt strips are secured to the back at their inner edges only have been found objectionable because or' the ent 1ance of the chalk dust and its retention between the inner parts of the strips from which it is practically impossible to remove the same in cleaning the eraser. In my construction, ver i little chalk dust can ent-er between the strips, because of the factthat they are held closely in contact with each other except near their rubbing edges.

vThe ends of the tape or binding member C being tied together or united intermediate the strips at the sides of the eraser, the union between the ends of said binding member, is located within the margins of the strips and is concealed from view and protected from injury by said strips.

rIhe parts of the binding member or tape, which are inserted through the strips as described, form in effect a series or plurality of strands, each vextending transversely through the several strips, at points between theinner and rubbing edges of' said strips, and engaged or connected at its ends with the outermost strips, in such a manner as to press or hold together, or maint-ain under compression, all of the strips, independently of, or separately from, the connection of the strips with each other afforded by the attachment of the edges of the strips to the back A. In the preferable construction illustrated, wherein the several transversely extending strands are formed by a single binding member or tape, the longitudinally extending parts of the tape serve to join the ends of the transversely extending strands with each other, and also to effect engagement of the strands with the outermost strips, thereby alfording a simple, strong and durable construction in an eraser having the practical advantages hereinbefore pointed out. It will be noted that the binding member has no connection with the back of the eraser.

I claim as my invention:

l. A blackboard eraser comprising aback,

a plurality of strips of erasing material arranged sid-e by side in contact With each other, and attached at their inner edges t0 the back, and binding means extending transversely through the strips intermediate their inner and rubbing edges; said binding means acting to join the strips With each other and hold the same under compress-ion, independently ot' the connection of the inner edges of said strips with each other by their attachment to the back; said binding means having no connection with the back and being independent of the means connecting the strips and theback.

Q. A blackboard eraser, comprising a back, a plurality of strips of erasing material arranged side by side in contact With each other7 and attached at their inner edges to the back, and a flexible binding member having parts Which extend transversely through the strips intermediate the inner and rubbing edges ot said strips, and other p parts of which extend longitudinally of and in engagement with the outermost strips; said binding member acting to join the strips Wit-h each other and hold the same under compression, independently of the connection of the inner edges of said strips With each other by their attachment to the back, and said binding member having no connection With the back and being independent of the means connecting the strips With t-he back.

3. A blackboard eras-er comprising aback, a plurality of strips of erasing material ar ranged side by side in contact with each other, and attached at their inner edges to the back, and a continuous flexible binding member having a plurality of parts extending transversely through the strips between the inner and rubbing edges of said strips; one of said transversely extending parts being located adjacent each end of said strips and the other of said transversely extending parts crossing each other and located intermediate the ends of t-he strips, and vother parts of said binding member extending longitudinally over the outer faces of the outermost strips, and integral with and connecting the transversely extending parts of said binding member; the ends of said binding member being secured together.

In testimony, that I, claim the foregoing as my invention I atlix my signature in the presence of two Witnesses, this 26th day of May, A. D. 1913.

FREDERICK A. I-IOLBROOK.

Witnesses:

CHARLES H. POOLE, EUGENE C. WAM.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C. 

